The vast majority of semiconductor device applications are satisfied employing epitaxial structures of ten micrometers or less in thickness. Therefore, it is not surprising that the conventional commercial MOCVD systems available today fall short of fulfilling the requirements for the growth of thick epitaxial layers having high structural integrity. The conventional systems begin to encounter problems when one attempts to exceed layer growths in excess of 15 .mu.m in thickness. Prior work in growing GaAs has used a V/III ratio of 11.7:1 (As/Ga) and a growth temperature of 650 degrees Centigrade.
The growth of semi-insulating films of GaAs by the MOCVD process was not practical before the publication of the work of Akiyama, et al., J. Crystal Growth, 68, 39 (1984), which reported that triethoxyvanadyl [VO(OC.sub.2 H.sub.5).sub.3 ] can be employed as an effective dopant which does not exhibit a memory effect. No data was presented on the physical properties of this material, nor were any caveats raised with regard to potential problems that must be addressed before TEOV can be used effectively without encountering any unexpected surprises.